1. Field of the Invention
The present invention relates to a code reader for reading a code from a recording medium on which sound data, image data, text data, or data that can be handled by a computer is recorded as an optically readable code to restore the data.
2. Description of the Related Art
A system in which digital data is divided into block units each including a predetermined information amount, recorded on a recording medium, and reproduced is disclosed in U.S. Pat. No. 5,866,895. In this system, each divided block data is read together with address data, and block data is combined based on an address to reproduce information. A configuration in which the data is divided into blocks, recorded, and reproduced in this manner is superior in expandability of data and reading flexibility, and even the data which cannot be stored in an image pickup screen is readable by scanning the code.
Furthermore, it is proposed in U.S. Pat. No. 5,724,364 that luminance information extracted from continuously picked-up frame images be fed back to a quantity of illuminative light or binarizing threshold value setting for the next frame image pick-up. In this system, an optimum quantity of illuminative light or binarizing threshold value can be set following luminance changes of an ever-changing code image during code scanning, and therefore the system is superior in that read defects are reduced.